Effect of echo time and T2-weighting on GRASE-based T1w/T2w ratio measurements at 3T

Tissue contrast can be enhanced by dividing T1-weighted (T1w) images by T2-weighted (T2w) images to map the so-called T1w/T2w ratio, which has become an increasingly popular technique for quantifying brain tissue changes associated with neurodevelopment, aging, and a variety of neurodegenerative diseases. However, although it is self-evident that T1w/T2w ratios increase with the amount of T2-weighting in the T2w image – which is determined by the echo time (TE), all else being equal – longer TEs also reduce the signal-to-noise ratio (SNR) of the T2w images, and it is not clear how these SNR characteristics affect the reliability of T1w/T2w measurements.
Source: Magnetic Resonance Imaging - Category: Radiology Authors: Tags: Original contribution Source Type: research